Apparatus for forming tubes



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a! SEPH AKITZJNBER.

United States Patent APPARATUS FOR FORMING TUBES John W. Miller, Toledo, .Ohio, and Joseph A.v Kitninger,

Spring Lake, Mich, assiguors to Oldberg Manufacturing Company, Grand Haven, Mich, a corporation of Michigan Application October 6, 1950,, Serial No. 188,134 2 Claims. (Cl. 113 -34) This invention relates to method and apparatus for forming articles from sheet metal and more especially to the production of cylindrical or tubular members from metal sheets.

The present invention embraces a novel method and apparatus for processing metal sheets into tubular formation utilizing a plurality of instrumentalities to perform successive opera-tions upon the sheets wherein edge configurations are impressed in the sheets at one-station, and the configurated sheets subsequently formed into tubular shape and abutting edge portions thereof interlocked in seam formation to provide a tubular shape at another station.

The present invention has particular utility in the formation of muffler shells or casings for sound attenuating devices especially usable with the exhaust systems of internal combustion engines. The construction of a muffler or sound attenuating device for use with an exhaust gas stream of an internal combustion engine includes the provision of a shell or casing'which may be of round or ovalconfigutation in c'rios's'sec'tion and is provided interiorly with sound attenuating chambers, baffles and gas passage means. The 'sh'ell'o'r' casing construction may be'of a single wall type or a double wall in which one wall may be ribbed, fluted or especially configurated to minimize shell noise. In order to assemble and properly correlate the interior elements in the shell or'ca-sing ccinstructionfit is imperative that the shell be of substantially uniformcross section throughout its length'in order to accommodate the interior elements and the head constructionssecui'ed to the ends of the shell.

The present invention comprehends the provision of apparatus especially adaptable for' producing muflier shells wherein uniform"dimension of' cross section is maintained throughout the length of the sh ell,the"apparatus being especially arrahg'ed and adapted td'produce large quantities of shells by automatic means.

An object of the invention resides in thepro'vision of apparatus adapted to config-urateopposin'g edge portions of one or more stripsor blanks'of :s'heetmetal utilized in forming a shell construction whereby stresses tending to impart improper distortion or twist tov the blanks are substantially equalized or eliminated.

The invention has for a further object the provision of an instrumentality adapted to subsequently receive and accommodate the blanks. having preformed edge portions, the instrumentality embodying automatically operated means for forming theblanks to closed. or tubular configuration and fabricating lock seams of the configurated edges by means of a movableca friagfi QP- erable with the blanks in relatively stationary pesition.

The method and apparatus of the present invention is inclusive of a blank receiving station, a station at which the ed e portions of the blank are lprecqnfigurated, an idle station adjacent the edge confi'tzuratingfstation and a fourth station'whereinflthe sheet i'sformed. to tubular configuration and extruded automatically after completion of the tubular formation. Through the utilization of the stations in the relation and sequence above mentioned, the method and apparatus are extremely reliable in fabricating tubes or shells of a uniform dimension with a minimum of liability of the apparatus becoming deranged whereby waste caused by improperly formed blanks is greatly reduced.

Another object ofthe' invention is the provision pf 2 a series of instrumentalities automatically operative in sequential relation forproducing tubes from sheets or blanks of metal wherein a sheet disposed at one station is maintained in relatively stationary position during the operation of. preforming the edges thereof and wherein the formedblank is conveyed to another station at which the blank is formed to tubular configuration and a lock seam completed to establish and fix the tube size Without liability of distortion.

A further object of the invention is the provision of a method and apparatus for forming a tube in which edge portions of the blank are preconfigurated in a vertically acting, hydraulically operated press whereby the edge configuration will be of uniform character throughout the length of the blank and without incurring any liability of twist in the blank.

Another object of the invention is the provision of instrumentalities especially adaptable and adjustable to form'tubes of various dimensions and shapes whereby the utility of the apparatus is greatly enhanced so that sheet metal tubes or muffler shells of different sites and shapes may be fabricated upon the apparatus through the novel method disclosed.

Another object of the invention resides in the provision of apparatus including an assembly of mechanisms in which hydraulic actuating means and electrically en} ergized control means are utilized for initiating and carrying out the operations of the mechanisms in feeding the blanks, in forming the edge portions of the blanks audin bending and seaming the blanks to tubular configuration, these operations being automatic in chafracte'rre'quiring' a minimum of supervision on the part of the operator.

Further objects and advantages are Within the scope of this invention such as relate to the arrangement, ope'ration and function of the related elements of the. structure, to various details of construction and to combinations of parts, elements per se, and to economies of manufacture 'and' numerous other features as will be apparent: from a consideration of the specification and drawing of a form of the invention, which may be preferredjin which:

Figure 1 is a semidiagrammatic elevational view il- Iustrating the several stations and the apparatus or instrumentalities for carrying out the sequential steps or operations of the method of the invention;

Figure '2 is an elevational view of a press construction for configurating the edge portions of a shell blank; Figures is an end view of the structure shown 'in'Figure 2, certain parts being shown in section for purposes of' illustration; Figure 4 ha side elevational view of the apparatus or instfiiinentalities for bending the blanks to tubular configuration and forming a lock seam therein;

Figure 5 is an end elevational view of the upper portion 'of the construction illustrated in. Figure 4;

Figure 6 is a vertical transverse sectional view through the apparatus illustrated in Figure 4;

Figure 7 is a sectional view taken substantially onthe line 7-7 of Figure 6;

Figure 8' is a detail view illustrating a shell blank bent into tubular configuration, the view showing the bending instrumentalities; i "Figure 9 is a side elevational view of a carriage or mefcihiinism for forming and completing, the lock seam of as e ';v

'Figure 10 is a bottom plan view of the mechanism illustrated in Figure 9;

Figure 11 is a sectional view takensubstantially on the line. 11-11 of Figure 19 illustrating. one of the sets of scam forming rolls in engagement with a shell blank;

Figure 12 is a sectional'view taken substantially on the. line 12.12 of Figure 10 illustrating a series of seam forming rolls and their relation in performing an operation. upon the seam of the shell;

Figure 13 is a fragmentary sectional view illustrating the seam of the shell in partially closed position;

Figure 14 is a fragmentary sectional view illustrating the completed'seam formed in a shell;

Figure 15 is a sectional view'illustrating the formation of a muffler shell of oval configuration on the apparatus of the invention;

Figure 16 is a horizontal sectional view through a portion of the apparatus shown in Figure 4;

Figure 17 is a detail view of one of the blank moving dogs forming an element of the blank conveying means;

Figure 18 is a schematic diagram of the hydraulic or pressure fluid system for actuating various components of the mechanisms of the apparatus, and

Figure 19 is a circuit diagram of the electrically energizable instrumentalities for controlling various mechanisms of the apparatus.

Figure 20 is an end view of a double walled shell in position to be engaged by the lock seaming means.

While the apparatus illustrated in the drawings is particularly adaptable for carrying out steps of the method of the invention as utilized in forming tubes from sheets of metal and especially tubular shells for sound attenuating devices, it is to be understood that we contemplate the utilization of the principles of the invention in various forms of mechanism suitable for carrying out the method of the invention. It is further to be understood that the apparatus of the invention is readily adapted to form tubular objects from both perforate and imperforate metal sheets or blanks, or double Walled tubes in which one wall may be fluted or ribbed.

Referring to the drawings and first with respect to Figure 1 there is illustrated in semidiagrammatic representation apparatus for carrying out the method of forming tubes and the several stations or positions occupied by the metal blanks during the precessing thereof to tubular formation. A blank 22 is first received or deposited at a blank receiving station 10 and is subsequently moved to a station 11, the latter embodying a press instrumentality for forming edge portions of the blank preparatory to movement of the blank to an intermediate or idle station 12. From the idle station 12 the blank is conveyed to the tube configuration and lock seam forming machine or apparatus, this station being designated 13. After completion of the tube, it is ejected to a tube receiving station 14.

The blanks are supported upon transversely-spaced, parallel ways or bars 21, the portions of the bars at the is secured a yoke 44. The yoke 44 is formed with pairs of tenons 46 forming pivotal connections for links 48 as shown in Figures 2 and 3. The head construction 38 also supports a pair of depending brackets 50, the extremities of which are provided with shafts 51 forming pivotal supports for pairs of links 52. Mounted upon the tubular uprights 36 is a ram or press slide 54 provided with bearing bushings 55 which are bored to receive the tubular guides 36, the slide 54 being vertically reciprocable relative to the guides 36. The press slide 54 is integrally formed with upwardly extending projections 56 which are bored to receive shafts 58 to which are pivotally connected pairs of links 60. The pairs of links 52 and 60 are pivotally connected together and to the links 48 through the medium of pivot pins 61 forming a toggle linkage system whereby the downwardly acting pressure of the slide 54 as it approaches its lowermost position is greatly increased through the medium of the toggle linkage hereinbefore described.

The extreme limit of downward movement of the piston 41 and piston rod 42 is determined by an adjustable abutment screw 65 threadedly supported in a boss 66 formed at the upper portion of the press slide 54, the abutment 65 being locked in adjusted position by means of a nut 67.

The die elements carried by the bolster 34 and the press slide 54 are preferably of adjustable character so as to enable the fabrication of tubes of different sizes and cross sectional shapes. As particularly shown in Figures 2 and 3, the lower die supporting elements 79 are mounted upon the bolster or bed 34 and are provided with portions 72 extending into transversely disposed T-slots 73 so that the elements may be adjusted toward or away from each other by traverse in the T-slots 73. Disposed centrally of each of the elements 70 is a depending member 75 which is bored and threaded to receive a threaded member 76 having a rectangularly shaped tenon '7 7 adapted to receive a crank (not shown) whereby each of the elements 70 may be adjusted by rotation of the threaded blank receiving station 10 being mounted upon upright supports or struts 18. The blanks are arranged to be successively moved to the several stations by means of a reciprocable slide or bar 19 provided with pivotally supported blank engaging dogs 20, 20' and 20", one of which is shown in Figure 17, the dogs beingmounted upon brackets 23 spaced sufficient distances along the slidable bar 19 to accommodate a blank between adjacent dogs. The brackets 23 carrying the blank engaging dogs may be adjusted along the bar 19 to accommodate blanks of different lengths if desired.

The blank conveying or actuating bar 19 may be driven by suitable means as for example a hydraulic cylinder 24 in which is disposed a piston (not shown) connected to a piston rod 25, the latter being connected by means of a bracket 26 with the reciprocable bar 19. Pressure fluid may be alternately introduced at opposite ends of the hydraulic actuator or cylinder 24 so as to periodically reciprocate the piston rod 25 and bar 19 for successively advancing the blanks to and through the several stations.

The apparatus for forming or flanging the edge por- I tions of the blank to prepare them for lock seaming operations and for impressing a partial concave configuration to the blank preparatory to its being formed into complete tubular configuration is illustrated in Figures 2 and 3. The apparatus shown in these figures is identlfied as station 11 in Figure 1. With particular reference to Figures 1 to 3 inclusive the press construction or mechanism for performing the first operations upon the blank is inclusive of a frame construction having base members 30 upon which are disposed uprights 31 carrying horizontally disposed beams 32 upon which is mounted the press table or bolster 34. Mounted upon the bolster or press bed 34 is a plurality of tubular members 36, the upper ends of the tubular members supporting a head construction 38. The end portions of the tubular members 36 are provided with threaded ten- 0 11s 38' adapted to receive nuts 39 for securing the uprights to the bed 34 and to the head construction 38.

The head 38 of the press supports a hydraulic actuator or cylinder 40 in which is reciprocably disposed a piston 41 connected to a rod 42 to the lower end of which member 76.

Secured to each of the plates 70 is a blank positioning or locating bar 79 which is secured to a backing plate 80 mounted upon the element 70. The plates 79 are adapted to properly position or locate the blank 22 beneath the upper die elements. Die members 81 of hardened steel are secured to the elements 70 and are adapted for cooperation with die members carried by the press slide for configurating edge zones of the blanks. Die positioning or locating blocks 82 are disposed adjacent an exterior stirface of each of the die supporting elements 70 and are adapted to be engaged by the die members as shown in Figure 3 to positively locate each element 70 so that a sheet metal blank of a predetermined width to produce a particular size of tube will properly fit between the guide plates 79. When it is desired to produce a shell or tube of smaller diameter, the members 70 may be adjusted inwardly toward one another by rotation of the members 76 until an inner face of each of the members 70 contacts or abuts surfaces of locating blocks 84. The use of the sets of blocks 82 and 84 thus selectively provides positive locating means for the dies for blanks of different widths.

The press slide carries the male elements of the die assembly for preforming edge portions of the shell blank and imparting partial curvature thereto. As particularly illustrated in Figure 3 a pair of similarly shaped blocks or elements 86 are carried by the press slide 54. The elements 86 are each provided with a bracket 88 which has a threaded opening to accommodate a threaded member 89, each member being formed with a rectangularly shaped tenon portion 90 adapted to receive a crank for adjusting the elements 86 in the same manner that the plates or elements 70 supporting the lower dies may be adjusted. The press slide 54 is formed with transversely arranged T-shaped slots 92 in which blocks 93 carried by the elements 86 are adapted for traverse so that the latter properly move in a transverse direction without binding duringrotation of adjusting members 89. After the elements 86 have been adjusted in this manner, they may be locked by means of securing bolts 95.

It is desirable in the formation of a mutfier shell or tube to impress a partial curvature in the blank prior to its reception into the forming and lock seam producing mechanism in order to facilitate the wrapping or binding of the blank upon a sizing mandrel. To this end each of the blocks 86 is adapted to support a die member 97 which is formed with acurved surface "portion adapted to in ga'ge and bend the blank to the-configuration shown -in broken lines in Figure 3., The edge portions of the 'blank are adapted to be simultaneously formed to arr-offset or flanged configuration as illustrated in Figure 5, and in order to produce the fianged configuration, hardened plates '99 are secured to the upper die supporting :blocksor elements 86 which cooperate with the dies =81 for such purpose.

The members 86 and -97 are transversely adjustable as hereinbefore mentioned and are positively located in their proper selected positions by means of a block 100 which is secured to the press slide 'bymea-ns of a bolt 101. Opposed pairs of faces onthe rectangular block 100 are so dimensioned that when the block is disposed Zin -on'e position, the opposed faces are abutted'by the members 86 to position the die blocks 97 in position "to form a blank of a particular size. When a blank of a different width is utilized the abutment block 100-isrotated through and the opposite faces thereof gthen position the blocks 86 to fit a blankof a different size. Thus "through the cooperation of abutment block and the threaded members 89, the upper :die elements 9-7 may be quickly and-readily yet positively adjusted to take care of blanks of different widths.

The mechanism and apparatus disposed at station 13 for forming the blank into tubular configurationand lock seaming theformed tube is shown in Figurestlft'hrough 1:2. With particular reference first to Figure 4, the mechanism is supported upon a frame which is inclusive of a base formed of a pair of inverted channels '106 provided with adjustable leveling screws 108for stabilizing orlleveling the machine upon a floor or support. Mounted upon the channels 106 are vertically disposed pairs :of bars or channel members 110 and .11 1 which are welded onotherwise secured to the inverted channel members.

The vertically disposed pairs of channelzmembers are joined together by twosets of channel members .1'14and 116 which are bolted or otherwise :fixedly joined to :the

vertical members. The upper ends of the pairs of vertical channel members 110 are joined together by transversely extending plates 118. Dependingifrom the plates "1118 is a pair of longitudinally extending channel .shaped members 120 which projectbeyond the pairs of vertical members 11d and 111 as illustrated in Figure 1. Through the arrangement of channel members and plates above described there is provided a frame construction which is strong and rigid and which maybe fabricated or built up from conventional structural metalsections. Theend portions of the horizontally extending'c'hannels 2120 .sup-

port pairs of members or=casings 122 .whic h-suitably enclose antifriction bearings journally supporting shaftsf124 and 125.

The members 122 enclosing the beanngsare secured to the frame by means 'of'bolts i127. Mounted fcentrally upon the shafts 124 and 125'are sprockets r128and Disposed at each side of sprockets 128 811(17129 are=pairs of smaller sprockets =130and 131, the l'a'tternbein'g fixedly secured to the shafts 3124 and 125. The pairs of'smaller sprockets 130 and 131 are fitted with chains, the ends of which are respectively connected to'yokes i133 :and 134 in the manner shown in Figured. Theyokef1-34 "is secured to one end of a pistonrod1136 while-the yoke 133 is secured to the opposite end ofthero'cl. 'T lihezpistonrod 136 extends through a :cylinder *1-"37 dnwhich is disposed apiston 139 secured to the. rod. Suitable'sealing or stutf ing glands 140 are provided-at: the ends'of .tthe.'cylinders for preventing leakage of'ifluid'alongthe pistonz'rod.

The piston 139 is reciprocated'inithezcylinder ethrongh the admission of pressure fluid alternately rtotherentls of the cylinder 137. Recipro'cation ofthe piston :causes the chains 13b and 131 to rotate the :shafts 124 and 125 i'cau'sing rotation of the larger sprockets 128,.and 1*29 toreciprocate a chain 142 fitted over the largensprockets. "The chain 142 is connected to a:carriage"=1'44 adapted'to perform lock seaming operations in :forming --.a tube and to extrude or strip thecompleted tube ."from a mandrel in a manner hereinafter described.

Turnbuckles 146 are interconnected with -"the :chain's 130 and 131 in order-to adju'st theprop'ertensioh, and

chain 142 is fitted with a turnbuckle 147 for adjusting the tension in the chain system 142.

'Secured to the pair of frame members 1 10by means of bolts 150 is a yoke-like member 151 shown particularly in Figure'S which supports a mandrel or=arbor 15-3.

The mandrel is provided with a shaft or tenon portion 154 which extends into a suitable bore formed inmemiber 1 51, the member being formed with a kerf -157 providing, in effect, a split collar formation, the adjacent portions being bored andone portion threaded to accommodate a clamping bolt 159 for clamping the tenon 154 securely in the mandrel support 151. As particularly shown in Figure 4, the arbor or mandrel 153 extends longitudinallyof the frame structure and in parallelism with the direction of travel of the lock seam forming means mounted on the carriage 144. The arbor orrmandrel 153 is shaped to provide a form about which the metal blanks, received from the edge forming press or station 11, may be bent or wrapped into tubular configuration.

Themeans for forming the blank to tubular configura- .=tion and lock seaming the meetingedges thereof will now be described. Disposed vertically of the frame and connected to the pairs of horizontally extending channel members 114 and 116 are spaced vertical guides or ways 1'60 and 161 which are fixedly secured to the channel members by suitable means. The loweroutwardly extending flanges of the channels 114 are connected together by a plate 163 which is secured thereto by means of bolts or other securing means. Mountedupon the plate 163 is an hydraulic actuator .164 including a cylinder 165 provided with a head portion 166 through which projects .a piston rod 167 provided with a piston .168reciprocably disposed within the cylinder 165.

Fhe upper end of the piston rod 167 projects through an opening in a member or yoke 170 and is fixedly secured thereto by means of a nut 171. The yoke construction includes a horizontally disposed plate portion 173 provided with pairs of brackets 174 as illustrated in Fig- 1ures 6 and 7, thebrackets being secured to the plate 173 by means of the screws 175. In the embodiment illustrated there are two pairs of bracketseach pair being formed with sets of aligned openings to accommodate the pivot shafts or pins 177. The central portions 178 of each of the pivot pins 177 is of a slightly larger diameter than the end portions. The links-180, at their lower portions, are provided with bearing bushings 181which form :journal or pivotal connection with portions 178 of the shafts 177. The upper portions of the links 180 are bifurcated and the furcations bored to accommodate bear- .ing bushings 1'82 through whichextend shafts 184 having tenon portions 185 received in openings formed in the lower portions of members or arms 187 illustrated in Figures 6 and 7. The arms .187 are bored to accommodate shafts 1'89, each having tenon portions 190extend- :ing into suitable openings in the arms. The arms of a yoke rnember 192 are bored to accommodate bearing bushings 194 which receive the central portions of shafts 189-and serve as supporting means for the blank bending and clamping arms or members 187.

Disposed in the spaces between the pairs of furcations formed at the upper ends of the links 180 arerollers 196 :arranged to engage guide or cam surfaces 197 formed on blocks or elements 198 which are secured to the channel members 116'by means of screws 199 as shown in'Figure '6. The function of the cam surfaces 197 is to control the path of movement of the arms and blank engaging -means for wrapping a blank around the mandrel 153. Asillustrated in Figure 6, the screws 199 pass through vertical slots 200 in the Web portions of the channels 116 and secured to thelower flangesof the channel members 116 are plates 202 which are bored and threaded to receive adjusting screws 203 for facilitating vertical adjustment of the cam blocks 198s0 as to regulate or accurately control the locus orpath of movement of theblankbending ar'ms or means 187. The screws 199 may be drawn up to secure the cam blocks in adjustedposition.

The upper ends of the arms 187 support plates 204 which in turn carry longitudinally extending bars 206 which extend in parallelism with the mandrel 153. The upper portions of the bars 206 are recessed or notched to accommodate and receive inserts or wear plates 208 which are secured to bars 206 by screws or othersuitable means. The inserts 208 are preferably fabricated of hardened steel or the like as they directly engage the'blank and wrap or foldthe same into tubular for'ma'tion around the mandrel 153 in a manner illustrated in Figure 8.

As shown in Figure 4, blocks 210 are secured to the yoke members 192 by means of screws 211. The blocks 210 are received in suitable verticall-y disposed ways vor rguides 212fixedly secured tothe-fraine of "the machine,

and the blocks 210 are constrained to move in a vertical direction under the influence of the guides 212.

It is imperative to the successful operation of forming tubes on the machine that the rollers 196 be maintained in contact or engagement with the cam surfaces 197 throughout the entire movement of the arms 187 in forming a blank around the mandrel 153. In order to accomplish this result, the yoke 192 is provided with a hydraulically controlled means arranged to exert a biasing force controlled through a relief valve influencing the rollers 196 to remain in engagement with the cam surfaces 197. As shown in Figure 4 there is provided two sets of cylinders, each set including a comparatively small cylinder and a larger cylinder designated respectively 214 and 215. Disposed in each of the larger cylinders 215 is a piston 217 carried by a piston rod 218, each piston rod being connected to one of the blocks 210 whereby each yoke 192 is under the influence of a hydraulic force set up in each of the cylinders 215.

Means is provided to clamp and hold the blank to the mandrel 153 after the blank is moved from the idle station 12 into a position coextensive with the mandrel 153. This means is inclusive of a bar 220 coextensively arranged with respect to the mandrel 153 and directly beneath the latter as illustrated in Figures 4 and 6. Secured to the bar 220 are depending rods 222 having enlarged portions 223 extending respectively into a bore contained in each of the yokes 192 as shown in Figure 4. The enlarged portion 223 is engageable with the ledge portion formed by the recess in the yoke 192 which serves as an abutment to determine the initial position of the bar 220 when the latter is out of engagement with a blank. Secured to the enlarged portion 223 of each of the rods 222 is a piston rod 224 which extends into a small cylinder 214 and is provided with a piston 226 adapted for vertical reciprocation in the cylinder.

Fluid connections 228 and 229 are provided at the respective ends of each of the larger cylinders 215 for facilitating the flow of pressure fluid to and from the cylinders 215. As will be apparent from Figure 4, a fluid conveying tube 239 connects the upper end of the cylinder 215 with the lower end of the smaller cylinder 214. The fluid conveying tube 229 is provided with a pressure reliefvalve 232 for a purpose to be hereinafter explained. In the operation of this mechanism, a metal blank is in position beneath the mandrel 153 as the yokes 192 move upwardly under the influence of the hydraulic actuator 165 acting through the sets of links 180. The initial movement of the yoke 192 permits the bar 220 to be moved to clamp the blank to the mandrel by reason r of the fluid above the pistons 214 in the cylinders 215 being driven through the tubes 230 into the smaller cylinders 214 and beneath the pistons 226. In this manner the initial movement of the yokes 192 carries the bar 220 into contact with the blank and forces the latter against the mandrel 153. Thereafter, further upward movement of the yokes 192 under the influence of the hydraulic actuator 165 is carried on against a lesser counteracting fluid force in the cylinders 215 above the pistons 217. The regulator 232 is set at a desired relief pressure so that as the yokes 192 continue upward movement, fluid from the cylinders 215 is ejected through the tubes 229 to a reservoir or fluid supply. In this manner the pressure of the fluid above the pistons 217 in the cylinders 215 constituting a biasing force resisting upward move-r ment of the yokes 192, hence maintaining the rollers 196 in constant contact or engagement with the cam surfaces 197 of the blocks 198.

Means is provided to receive and guide the blank into proper relation with the mandrel 153 as it is ejected into the tube configurating and lock seaming machine from the idle station 12. This blank positioning and guiding means is best illustrated in Figures 4, 5 and 6. Mounted upon the upper flanges of the horizontal channel members 116 are spacing blocks or members 234 which support guide block assemblies 235 each assembly including a horizontal plate 236 and vertical plates 237 and 238. The latter plate 238 is provided with ledge portions 239 adapted to receive the edge portions of the blank so as to properly position the blank transversely with respect to the arbor or mandrel 153. The vertical plates 237 are preferably welded or otherwise secured to the horizontal plates 236, the latter being secured to the spacing members 234 by means of screws 240. The plates 238 are removably secured to the vertical plates 237 by means of screws 241 whereby plates of different dimension may be used to accommodate blanks of different widths.

The blanks after being formed into tubes are extruded by the carriage 144 in a manner hereinafter explained and are received upon a shelf or table 245 supported by one pair of frame uprights as shown in Figure 4. Brackets 246 are secured to the uprights 111 and directly support the table 245.

The carriage bearing the lock seam forming means particularly shown in Figures 9 through 12 will now be described. The carriage 144 is formed with a body or plate 250 which has an upwardly extending central portion 251 which is adapted to be received between supporting plates 253 secured by bolts 254 to the lower flanges of the horizontal channel members 120. The plates 253 form guide means to direct the carriage body 250 in a,

rectilinear direction parallel to the longitudinal axis of the mandrel 153. The body 250 is held in proper reciprocatory sliding engagement with the plates 253 by means of the retaining plates 256 secured to the body member 250 by means of the screws 257. Mounted at each end of the carriage body 250 are the brackets 259 which are adapted to be connected to the ends of the chain 142 by means of pins 260.

The lower surface of the body plate 250 of the carriage is adapted to support a plurality of plates 261, 262, 263, 264 and 265, each of the plates 261, 262, and 264 supporting a single roll, these being respectively designated 267, 268 and 269 while plates 263, and 265 are provided respectively with pairs of rolls designated 270 and 271, the several rolls performing a sequence of operations upon adjacent edges of the blank to form and complete a lock seam.

The operation of forming a lock seam on the blank takes place during movement of the carriage 144 in a righthand direction as viewed in Figure 4. Figure 11 illustrates the engagement of the rolls 271 with the juxtaposed edges of the blank 22 held in the position shown in Figure 11 under the influence of the bending fingers 208. As shown in Figure 11 the rolls 271 engage the juxtaposed edges of the blank to bring them into close engagement so that the succeeding roll 269 will flange or bend one edge portion of the blank partially over the other edge. The rolls 270 then engage the overlapping edge portions of the blank in the manner shown in Figure 12. The roll 268 engages the overlapping edges of the blank to move the same to the configuration shown in Figure 13. The final seam closing or seam completing operation is performed by a single roll 267 mounted on the plate 261, this roll engaging the overlapping edges as they appear in Figure 13 and form them to the configuration shown in Figure 14, thus completing the lock seam formation so that the blank is then fixedly configurated to a tubular configuration. When the carriage has completed its stroke or movement in a righthand direction as viewed in Figure 4, all of the rolls 267 through 271 inclusive will have engaged and performed their inlcjlividual operations upon the juxtaposed edges of the lank.

The carriage 144 is provided with means for ejecting or extruding the completed tube when the carriage is moved in a lefthand direction as viewed in Figure 4. As particularly shown in Figures 9 and 10, the pivot shafts 274 upon which the roller 267 is journaled also forms a pivotal support for a dog 275 which is provided with an abutment surface 276 adapted to engage the rear of a completed tube to eject the same from the mandrel 153. The lower surface of the abutment portion '276 is concavely curved so as to coincide with the cylindrical surface of the mandrel 153 so as to assure that the abutment surface 276 will engage and strip the finished tube from the mandrel. A hairpin type spring 278 engages in an opening formed in the dog 275 and with the bracket 259 to'bias or urge the dog at all times in a direction toward the axis of the mandrel 153.

In order to minimize the friction between the carriage 144 and the ways 253, means are provided for lubricating the engaging surfaces. As shown in Figure 11, the upper surfaces of the body or plate 250 are provided with felt pads 280 which are impregnated with a suitable lubricant. "ln this manner the lower surfaces of the plates 253 are adequately lubricated. A supply of lubricant is contained in a strip of felt 281 disposed above the carriage body plate 250 which is held in place by apes-oat means of a plate 282. The body 250 is provided with channels (I1OtfihOWli) for conveying lubricanttirom the felt 281 to 'the journals supporting it-he severals'eam forming rolls so as to provide adequate lubrication therefor.

The various instrumentalities of *the apparatus of the present invention --are actuated 'by nun pressure acting upon or through hydraulic actuators. Figure 318 illustrates diagrammatically the hydraulic fluid pressure circuits for carrying out the-operations of the several mechanisms. The hydraulic mechanisms for carrying on the various operations are set intooperati'on and controlled by electrical means, a circuitof the electrical means being diagrammatically illustrated in Figure 19.

With particular reference to Figure 1 8, :th'er'e is illustrated acontainer or reservoir :285 adapted-to contain a supply of oil or other :liquid for actuating the various instrumentali-ties of the system. A suit-able *pump 287 driven by a motor 288 is c'onne'cted'to the reservoir by means of a:tube'289 torconveying liquid from the reservoir to the pump. The 'pump supplies fluidu-nder pressure 'throughthe line 290 to the four way valves 29 2 and 293 which are electrically controlled. The four-wa'y valve .292 is connected with the press aetuator w and-"the actuator 164 which operates the clamping arms and bars for folding or wrapping the blank around the mandrel "153. The four way valve 293 is connected with the cylinder 24 for reciprocating the blan'k ieeding plate 19 in alternate directions and to actuate the pis' tonin-cylind-er 137 for reciprocating "the carriage in one direction to form a lock seam in the tubeand in the other direction to strip the tube from the mandrel 15'3. Phe four way valves 292 and 293 are of the pilot operated type wherein pressure fiuid actuates a pilot mechanism for moving't'he valve uni-ts contained in-thesemechanisms, the pilot mechanism thereof being solenoid operated. The fiuid lines'of the pilot mechanisms are indicated in broken lines in Figure '18.

The hydraulic actuating cylinder 21 1 "for initially moving the blank clamping 'bar 220 i-n-to engagement with a "blank beneath the mandrel 158, and the-cylinders 215 for setting up counterresis'tance' to the-upward movement of the yokes 192 are connected by tubes F300 and 229-with the :pressure tube :290 and "the fiuid return tube 291.

Check valves 303 interoal-ated in theseiltiidilines inorder to insure-proper direction of flow of liquid in the lines during operation =o'f-the actuators 21and 215. As the 4-way valves,r.the hydraulic actuator cylinders and-piston :units, v:the regulator and cheek-valves are 'of conventional cde'sign, it is believed unnecessary to further desoribe the hydraulic circuits in detail :as Figure "18 clearly illustrates the fluid connections through the various actuators from thepump 287.

The electrical-circuit illustrated in-JFi-gure 19 is of conventional character and is inclusive of solenoid means for operating the 4 way valves, and-current relays and ilimit switches forsinitiating-t heproperaoperatingsequence of :the hydraulically operated instrumentalities. The

iinechariism-s are automatic in operation uponinitiating loperationof the motor 288 through' the motor-starting means 306 and the closing of the cycle starting switch 307. The solenoid coils 309 and 310 are associated with the 4-way valve 293 'for actuating the latter to successively operate the lock seam forming mechanism and for stripping the finished tube from the mandrel. The solenoids 31 1 and 312 control the action of the piston in the hydraulic cylinder 165 for moving the clamps to an up position and to a down position. The iluid circuits for moving the piston in cylinder '1-65 :are also connected with the press actuator 40 for controlling vertical reciprocable movement of the press slide in forming the edges of a blank received from the blank feeding or advancing means 19. The hydraulic actuator 24 for the blank feeding means 19 is intercalated with the 4 way valve 293 and the fluid pressure line leading to the lower end of the clamp actuating cylinder 165 whereby the blank feeding means is actuated in timed relation with the clamp actuating means.

The electrical system is inclusive of a plurality of limit switches of conventional character which control the sequence of operations of the various mechanisms. LSl represents a double throw limit switch which is operated at a point in the movement of the carriage when the latter is in a position completing the formation of a scam in the tube, viz. the position of the carriage 144 at the extreme righthand end of the mandrel 153 as viewed in 10 Figure 4. "is ta "normally open limit switch operated-when the farms or'lalmps 1 87 are in their'lowermost position. LS3 is in normally open limit switch which is controlled by the press :slide "and is moved to :elosed position when the press is in its initial or retracted position. LS-4 is a double throw limit switch which is operated when the carriage 144 has completed its cycle 'of stripping a finished tube from the rn'andrel 153, -i. e. in a position at the extreme left end {of .Figure 4. LSS is a normally open limit switch which is operated by the blank folding mechanism when-moved to its :upperposition in which it completes the foldingorwrapping of the blank about the mandrel 5553. LS- 65is-a5norm-ally open limit switch which -is 0perated when 'the press slide is in 13.) polsgtion forming theedgeorfflange configuration in the lan When the solenoid 309 is=energized, theyfiuid isadmitted to the cylinder 187 to strip-or eject afinished tube from the mandrel {5 3. -When the solenoid "310 is energized the fluid 'is admitted to the opposite end 'of the actuator 137 moving the carriage in the opposite direction to initiate and complete :a'lo'ck seam'formingoperation on the blank. -When-the solenoidf3'11'isenergized, the actuator 164isoperated-to'move the *arms 187 into operative engagement with the blank to wrap or 'form the latter around the -mandrel *lfiipand, simultaneously, the press slide is moved'downwardly byifluid injected. into the upper end of theh-ydraulic aactuator or cylinder 40. When the solenoid is energized, -the -flow of-fiuid .into cylinder 165 is reversed and the*arms 187 and associated mechanism move downwardly out-of --en gagement with the blankon-the mandrel *153 and simultaneously the 4 press slide or ramiis moved upwardly by flow of liquid tothe opposite end of cylinder The automatic cycle :above described may be supplemented by manual switching means for independently operating the various instrumentalities of the mechanism, if desired. For example, aneme'rgency stop switch 315 may be actuated which-will interrupt *the sequence of operations at "any stage. Kit is desired to operate the stripping movement of the :carria'ge independently of the other mechanisms, this may be accomplished by manual actuation of the-switch 317. "If it-isdesired 'to manually control movement of the Carriage 144 during a seam forming operation, this may be accomplished by manipulation of the-switch 318. Inorder to manually control the upward movement of the clamping arms 187 and associated mechanism, *this may be accomplished by manual switch 320, and if it "isdes'iredto-manually con- -trol the-downward movement of the arms 187 and associated mechanism this maybe accomplished by-manual i manipulation of the switch 322.

Theope'ration-of the several;instrnmentalities or mechanisms for producing-tubes is as follows: The blanks 22 preferably in the form of flat meta'l sheets, may-be fed bymanual :means to the ways '21 or they may-be con- .veyedito thestations 1"0 by automatic means. The'operator 'ithen closes :the 'cycle starting switch 307 (shown in Figure .19). The=-carriage whiohis in position at the extremerighthandzend of the mechanism as viewed in Figure 14 i starts its :stripping a'a'ction by movement in a lefthand direction, the dog 275 on the carriage engaging a finished tube upon the mandrel 153. When the carriage 144 is moving to complete a stripping cycle the limit switch 1.84 is operated and during this operation of the machine, the hydraulic actuator 24 receives pressure fluid through the four way valve 293 to move a blank carried thereby into the station 11, this being a position beneath the press slide 54. concomitantly with this movement, a blank having edges flanged in the press as disposed at the idle station 12 will be advanced or conveyed to station 13 by its engagement with the dog 20" carried by the blank feeding means 19. Assuming that a blank having configurated edges is moved from the idle station 12 to the tube forming and lock seaming mechanism of station 13, the cylinder 165 receives oil beneath the piston through the interconnecting four way valve 292 causing the blank forming means or arms 187 to move upwardly engaging the members 208 with the blank to wrap the same around the mandrel to the position illustrated in Figure 8. When the members 208 and arms 187 are at their uppermost limit of movement as illustrated in Figure 8, the limit switch LS2 is released and LS-3 a limit switch operated by the press slide, is released. When the blank bending or forming arms 183 reach their uppermost position, the limit switch LS-S is operated and at the same time the press slide or ram 54 is moved downwardly by the ingress of pressure fluid in the upper end of cylinder 40. The press slide 54, moving to its lowermost position forms the flanges at the edges of the blank and impresses partial curvature or concavity to the blank adjacent the flanged edges. The press slide 54 upon reaching its lowermost or closed position operates the limit switch LS-6. The carriage 144 then begins its return stroke during which the seam forming rolls 267 through 271 inclusive successively engage the juxtaposed edges of the formed blank on the mandrel 153 to facilitate the lock seam or configuration illustrated in Figure 14. The initial movement of the carriage 144 toward seam forming position releases limit switch LS4 and when the carriage reaches the end of its seaming stroke limit switch LS1 is operated. When the carriage 144 is stopped after completion of a seam, pressure fluid is introduced into cylinder 165 above the piston therein, moving the yoke 192, plate 173, linkage connected thereto and the blank bending arms 183 downwardly. This action releases limit switch LS-5 and pressure fluid enters the cylinder 40 beneath the piston therein at the same time that pressure fluid is admitted to the upper end of cylinder 165 causing the press ram 54 to move upwardly to its initial position. This action releases limit switch LS-6. When the plate 173 carrying the linkage and blank bending members 183 is at down position, the limit switch LS-2 is operated and concomitantly the press slide, reaching its uppermost or full open position, actuates limit switch LS-3.

The mechanisms have thus completed a full cycle of operations and will be repeated on succeeding blanks as long as the cycle starting switch is in energized position. The limit switches are supplemented by current relays of conventional construction exemplified in Figure 19 for facilitating the carrying out of the various functions of the electrically energized components of the mechanisms arranged to operate and control the hydraulic actuators and initiate their actions in proper sequence.

Figure 20 illustrates a form of double wall tubular member or muffler-shell in the position that it occupies after the double wall blank has been folded around the mandrel and before the carriage 144 has lock seamed the adjacent edges of the blank assembly. In this form of construction the inner wall 350 is of smooth or uninterrupted contour while the outer wall 351 is formed with spaced raised portions 352 separated by depressed portions or flutes 353, the metal of the depressed portions engaging the outer surfaces of the inner wall 350. In

some tubular constructions, the outer wall may be smooth and the inner wall corrugated or formed in the manner of the outer wall in Figure 20. In order to hold the double walls of the composite blank in proper relation during processing through the press at station 11 and the tube configurating mechanisms of station 13, it may be desirable to spot weld engaging portions of the double walls as indicated at 355 to avoid slippage of one wall with respect to the other wall during processing operations. The arrangement of the present invention is adaptable to form tubes of either single or double wall construction without modification of the apparatus.

lid

We claim:

1. Apparatus for forming cylindrical tubes from shee metal blanks including, in combination, a frame, a relatively-stationary, cylindrically-shaped mandrel mounted upon the frame, means for conveying sheet metal blanks having flanged edge portions from an adjacent station into a position adjacent the mandrel, a bar disposed in parallelism with the mandrel adapted to engage a flanged blank, hydraulic means for actuating the bar to bias the same in a direction to clamp a blank in contact with the mandrel, a plurality of pivotally supported arms disposed adjacent the mandrel, cooperating cam and cam follower means for guiding said arms, hydraulic means for actuating the arms in directions controlled by said cam and cam follower means to bend a flanged blank around the mandrel and interengage the flanged edges thereof, a carriage reciprocable in directions parallel with the mandrel, a plurality of forming rolls mounted on said carriage and engageable with the interengaged flanges of the blank for forming a lock seam to complete a tube when the carriage is moved in one direction, and a member mounted upon the carriage and biased into engagement with an end of the tube for stripping the tube from the mandrel when the carriage is moved in the opposite direction.

2. Apparatus for forming cylindrical tubes from sheet metal blanks including, in combination, a frame, a relatively-stationary, cylindrically-shaped mandrel mounted upon the frame, means for conveying sheet metal blanks having flanged edge portions from an adjacent station into a position adjacent the mandrel, a bar disposed in parallelism with the mandrel adapted to engage a flanged blank, hydraulic means for actuating the bar to bias the same in a direction to clamp a blank in contact with the mandrel, a plurality of pivotally supported arms disposed adjacent the mandrel, a roller associated with each arm, cam surfaces arranged to be engaged by said rollers for guiding the arms, electrically-controlled, hydraulically-actuated means for moving the arms to bend a flanged blank around the mandrel and interengage the flanged edges of the blank, a carriage reciprocable in directions parallel with the mandrel, a plurality of forming rolls mounted upon the carriage, said forming rolls engaging the interengaged flanges of the blank to form a lock seam when the carriage is moved in one direction, a member pivotally supported upon the carriage, and resilient means biasing the member into contact with the mandrel whereby the member engages the end of the completed tube and strips the same from the mandrel when the carriage is moved in the opposite direction.

References Cited in the file of this patent UNITED STATES PATENTS 343,024 Gordon et al June 1, 1886 563,255 Briggs July 7, 1896 1,459,905 Byerlein June 26, 1923 1,612,519 Lindgren Dec. 28, 1926 1,805,261 Roberts May 12, 1931 

